In the past year we completed the refinement and publication of C3d a C3 fragment and ligand for the CR2 receptor (see Science below). The structure was solved by MAD phasing at the Se edge from data collected at CHESS. The structure contains 8 selenium atoms and in collaboration with with Dr. David Smith, the data was used to illustrate the utility of the SnB method for determining the selenium substructure. The structure provides a model for the activation of C3 as well as insight into the basis for interaction with the CR2 receptor. We have also completed the refinement and publication of the CRD of human galectin-3 in complex with lactose and N-Acetylactosamine from data collected at CHESS. These molecules are important in modulating cell-cell and cell-matrix interactions. Our structure has defined the basis for carbohydrate-binding, and in addition provided insight into the mode of oligomerization, shown by this lectin. In addition, we collected data at CHESS on a C-type lectin and crystals of a CRE recombinase-DNA complex. In both cases the solution of these structures is in progress.